"Set Square" wrote in message
...
In an earlier contribution to this discussion,
don wrote:

I currently have a Potterton 16/22 boiler driving the central heating
via a pumped circuit, and the hot water cylinder via convection.

I'm looking to move the hot water cylinder from its current location
directly above the boiler (in the bathroom) into the loft. This will
involve a much longer pipe run with a number of kinks, so I'm guessing
I need to convert the system to be fully pumped?

From installation in 1973 my ground-floor wall-hung
Potterton 10-16 has been driving 28mm 'gravity'
pipes up to an indirect ho****er cylinder in the loft.
I'd guess the total height is 2 x 8'6" plus ceiling gaps
say ~20 feet? The pipes also have a number of kinks
as the heater is on an external wall and the tank is
about fifteen feet into the centre-line of the house.
As others have stated the cold water tank is mounted
on an over-engineered timber structure towards
the centre of the roof. Water is heavy.

--
Brian